Stilling basins in ponds?

[Quest101]

Are stilling basins usually used for pipe outfalls at channels or swales ?

Is it common to use Stilling basins at the outfalls of pipes going into the basins or ponds? It’s not too clear to me, in my PA e & s manual ( vague ), whether the S.B detail is only for channels?

Where would I get the derivation for the equations used to design Bs's.

Thank you!

Quest101

 

[TerryScan]

In Delaware, forebays (similar to stilling basins) are required where pipes discharge into ponds.

Stilling basin design equations are typically related to scour hole estimates.

 

[Quest101]

Thank you TerryScan for your response,

Would you happen to know where I can get the derivation for the stilling basin equations?
I don't see the similarity between the forebay and stilling basin, but I'm new at the subject anyway.

While on the subject what's the best way to position the pipe outfall in the basin, on the wall (thus using a riprap apron on an incline) or sitting at the bottom of the basin ( option of using rip rap apron or a stilling basin) ?

Thank you!